Railroad bed cribber



1970 e. 1'. BLACKWELL, JR 3,543,297

RAILROAD BED CRIBBER Filed Sept. 9, 1968 6 Sheets-Sheet 1 FIG. I

INVENTOR GEORGE T.

dam; mm

ATTORNEYS BLACKWELL,JR

Nov. 24, 19-70 a. 'r. BLACKWELL, JR

RAILROAD BED CRIBBER 6 Sheets-Sheet Filed Sept. 9, 1968 Ill 1970 e. T. BLAKWELL, JR 3,543,297

RAILROAD BED CRIBBER Filed Sept. 9. 1968 6 Sheets-Sheet 5 a. "r. BLACKWELL, JR Q 3,543,297

Nov. 24, 1970 RAILROAD BED CRIBBER 6 Sheets-Sheet 4 Filed Sept. 9. 1968 El W 1970 G. 'r. BLACKWELL, JR 3,543,297

RAILROAD BED CRIBBER 6 Sheets-Sheet 5 Filed Sept. 9. 1968 RAILROAD BED CRIBBER Filed Sept; 9. 1968 6 Sheets-Sheet 6 QNT 3,543,297 RAILROAD BED CRIBBER George T. Blackwell, Jr., P.(). Box 278, Oneonta, Ala. 35121 Filed Sept. 9, 1968, Ser. No. 758,557 Int. Cl. E01b 27/00 US. Cl. 37-104 10 Claims ABSTRACT OF THE DISCLOSURE A railroad bed cribber including a frame supported by wheels at its corners from the rails of a railroad track. A crawler is supported by the frame intermediate its ends and on one side thereof and can be lowered to support the frame from the road bed when the rail is removed from beneath the adjacent wheels of the frame. Cribbing or digging devices are mounted on opposite sides of the crawler along the edge of the frame and can be lowered into digging relationship with the railroad bed to clean the debris from between the cross-ties of the railroad bed. A jack is supported at the center of gravity of the frame, and is movable in a downward direction to engage the road bed and lift the frame from the tracks, whereupon the frame can be pivoted about the jack, to reverse its direction of movement along the rails, and to place the cribbing device on the opposite side of the road bed.

BACKGROUND OF THE INVENTION When repairing the rails or road bed of a railroad track, it is usually necessary to excavate or crib the material from between the cross-ties of the road bed. The road bed should be constructed so that gravel is placed between the cross-ties and the road bed slopes dwn wardly from its centerline, so that water will drain from between the cross-ties. This keeps the road bed free of water so that the cross-ties will not rot. Also, the removal of other dirt and debris from the road bed minimize the risk of termites or other insects from damaging the cross-ties.

In the past, the road beds of railroad tracks have been manually excavated, by workmen removing the rails of the track and manually excavating the dirt and debris from between the cross-ties. While various machines have been developed which mechanically excavate road beds, these machines have proven unsatisfactory because of their complicated and expensive construction, and because of their awkwardness of operation.

SUMMARY OF THE INVENTION Briefly described, the invention herein disclosed comprises a railroad bed cribber supportable on one of its sides from a rail of a track, and supportable on the other of its sides from the road bed or cross-ties of the track. The cribber is movable along the road bed and functions to progressively excavate or crib the debris from between adjacent ones of the cross-ties. The cribbing function is performed with the cribber in an upright, balanced condition, and the operation of the cribber can be controlled by a single operator. When the cribbing function has been completed, the cribber can be moved along the tracks at a higher velocity to a new location.

Thus, it is an object of this invention to provide a railroad cribber for cribbing or excavating the debris from between adjacent ones of railroad bed cross-ties.

Another object of this invention is to provide a railroad bed cribber which can be operated by a single operator, and which functions to throughly and rapidly ex- States Patent O cavate material from between adjacent ones of railroad bed cross-ties.

Another object of this invention is to provide a railroad bed cribber which is inexpensive and to manufacture, safe and versatile in operation, and which is useable and compatible with other railroad bed repair equipment.

Other objects features an advantages of the present in vention will become apparent upon reading the following specification, when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevational view, partly in section, of the left side of the cribbing machine, showing the crawler and cribbing drums in their respective raised positions for traveling to and from the site of operation.

FIG. 2 is an elevational view, partly in section, of the left side of the machine, similar to FIG. 1, but showing the operational positions of the crawler and the crib bing drums.

FIG. 3 is an elevational view of the right side of the machine, showing the jack extended and the machine turned through an angle of degrees with respect to the railroad bed.

FIG. 4 is a top plan view, partly in section, of the machine.

FIG. 5 is an end cross-sectional view taken along lines 5--5 of FIG. 2, showing the crawler and cribber in their respective operational positions on top of the road bed.

FIG. 6 is a detailed end cross-sectional view, taken along lines 66 of FIG. 2, showing the cribber drum and its relationship to the road bed in its operational position.

FIG. 7 is a detail showing of the top portion of the jack, showing the cylinder end and thrust bearing.

FIG. 8 is a schematic block diagram of the hydraulic system of the machine.

DESCRIPTION OF THE PREFERRED EMBODIMENT 14 and 15, and their respective wheels are driven by hydraulic motors 16 and 17, respectively. Motors 16 and 17 are connected to axles 14 and 15 by means of clutches 1'8 and 19, and chains (not shown) extending from the clutches and surrounding the respective axles.

Crawler 21 is positioned intermediate 'the ends of frame 11, and in alignment at the edge of frame 11 with wheels 12a and 12b. Crawler 21 includes stationary support frame 22 which is rigidly connected to and a part of frame 11 and crawler track frame 24. Crawler track frame 24 is generally T-shaped and includes vertical support stem 25 and track guide 26. Vertical support stem 25 is reciprocally received in stationary support frame 22, and movable vertically of stationary support frame 22 by means of double acting hydraulic cylinder 28. Track guide 26 extends longitudinally of frame 11 and includes rounded ends 29 and bottom edge 30 for receiving crawler track 31. Idler sprockets 32 are posi tioned on opposite sides of vertical support stem 25 at its upper end, and driving sprocket 34 (FIG. 5) is sup ported intermediate vertical support stem support plates 34. Thus, crawler track 31 is stretched about track guide 26, idler sprockets 32, and driving sprocket 35. Double acting hydraulic cylinder 28 functions to lower or raise crawler 21 with respect to frame 11, as desired. Locking plate 36 is rigidly supported by adjacent vertical support stem 25 from stationary support frame 22. Locking plate 36 defines apertures 38 therein, while vertical support stem 25 defines apertures 39 there through, and apertures 38 and 39 can be aligned with each other when crawler 21 is raised by means of double acting hydraulic cylinder 28. Retaining pins 40 are insertable through the aligned apertures, to positively hold crawler 21 in an elevated position, as is shown in FIG. 1.

As is best shown in FIG. 5, driving sprocket 35 is driven by a pair of hydraulic motors 41 and 42, which are supported exteriorly of support plates 34.

As is best shown in FIGS. 1 and 2, cribbers 44 and 45 are positioned on opposite sides of crawler 21. Each cribber 44 and 45 is supported, and movable vertically on a stationary support frame 46 and 47, respectively, and single acting hydraulic cylinders 48 and 49 function to lift the cribbers with respect to their respective frames. Each frame 46 and 47 includes a plurality of V-shaped rollers or bearing 50 and 51 which are positioned inwardly of frames 46 and 47, and each cribbed 44 and 45 includes a housing 52 and 53, respectively, which have vertical support tracks positioned on opposite sides thereof for engagement with bearings 50 and 51, respectively. Vertical tracks 54 and 55 are beveled so that their beveled edges mate with the V-shaped bearings, so that cribber housings 52 and 53 are movable vertically With respect to their respective stationary support frames 46 and 47. Housing 52 and 53 are restrained from downward movement by means of locking chains 56 and 57 which connect the ends of housings 52 and 53 to the upper portion of their respective frames 46 and 47. Chains 56 and 57 are placed in retaining hooks 58 and 59 so that when housings 52 and 53 are allowed to move in a downward direction by their respective hydraulic cylinders 48 and 49, locking chains 56 and 57 will become taut to prevent further downward movement of the housings; however, housings 52 and 53 will be free to move in an upward direction.

Cribbers heads 60 and 61 are rotatably supported by axles 62 and 63 within their respective housings 52 and 53. Axles 62 and 63 extend longitudinally of cribber 10, and cribber heads 60 and 61 are constructed in a manner as taught by US. Pat. No. 3,126,656, issued Mar. 31, 1964. Each cribber head 60 and 61 includes a plurality of support discs 64 spaced along axles 62 and 63, and cribbing tines 65 pivotally supported between support discs 64. Cribbing tines 65 are connected by coil tension springs (not shown), so that when the end of tines 65 engage an unmovable object, such as a railroad cross-tie, the individual tines will pivot and will not break. As is shown in FIG. 6, the ends of each tine 65 is bent at an angle, so that when the tines rotate in the direction as indicated by arrow 66, the ends of the tines act as a shovel, and will dig into the debris or earth between adjacent cross-ties of the railroad bed. As the earth is extracted by tines 65, a major portion of the earth will be thrown against the housings 52 and 53 of the cribbers. In order to dampen the movement and noise created by the earth and debris, the lower portions 68 and 69 of each housing 52 and 53 is fabricated of a resilient material, such as rubber.

Cribber drum 60 and 61 are motivated by hydraulic motors 70 and 71 which are mounted on the top of housings 52 and 53. Each motor 70 and 71 is connected to a drive chain which extends into its respective hous ing and about the axle of its respective cribber drum.

As is best shown in FIGS. 4 and 5, jack 75 is located centrally of frame 11 and includes foot or pedestal 76, support shaft 71 which extends upwardly from pedestal 76, and double acting hydraulic cylinder 78 which is connected to the upper end of support shaft 77 and to frame 11. Support shaft 77 is maintained in a vertical attitude by bearing 79. As is shown in FIG. 7, support shaft 77 is pivotal with respect to hydraulic cyl inder 78 by means of bearings 80. Thus, pedestal 76 and frame 11 are rotatable with respect to each other, about a vertical axis.

As is best shown in FIGS. 3 and 5, retaining rollers and 91 are positioned adjacent wheels 12c and 12b. Retaining rollers 90 and 91 are each supported by support rod 92 and 93 which are reciprocally received within support housings 94 and 95. Support housings 94 and 95 each include a locking aperture (not shown), while each support rod 92 and 93 define a plurality of locking apertures (not shown) which are alignable with the locking apertures of their respective support housings. Thus, retaining rollers 90 and 91 can be elevated as desired, and locking pins 96 and 97 can be inserted through the aligned locking apertures to lock the retaining rollers at their desired elevation.

Each retaining roller 90 and 91 includes a flange, such as flange 98 (FIG. 5) of roller 90, for engaging the rail upon which wheels 12c and 12d are supported, on the side of the rail opposite from that facing the flange of the wheels. With this arrangement, the flanges of retaining rollers 90 and 91 and the flanges of wheels 12c and 12d function to maintain cribber 10 aligned along one of the rails of the track.

As is shown in FIGS. 3, 4 and 5, internal combustion engine 81 is supported on frame 11, on the side of frame 11 opposite from cribbers 44 and 45 and crawler 21. Engine 81 can be either a gasoline engine or diesel engine, and is completely self contained with battery 82 and a complete electrical system (not shown). Engine 81 is connected through clutch 84 and chain connections 85 to'pumps 86 and 87. Pumps 86 and 87 function to operate hydraulic cylinders 28, 48, 49, and 78, and hydraulic motors 16, 17, 41, 42, 70, and 71, as is best shown in the block diagram of FIG. 8.

Hydraulic sump 100 is also positioned on the side frame 11 opposite from cribbers 44 and 45 and crawler 21. Sump 100 is positioned on the end of frame 11 opposite from engine 81. Thus, sump 100 balances its end of frame 11 with respect to engine 81, and sump 100 and engine 81 balance their side of frame 11 with respect to crawler 21 and cribbers 44 and 45. Pumps 86 and 87 are connected to sump 100, and the exhaust of the various hydraulic motors and hydraulic cylinders are also connected to sump 100, so that a closed hydraulic system is created.

As is best shown in FIGS. 3 and 4, control panel 101 extends across the end of cribber 10, adjacent cribber 44. A series of valves 102 are connected to control panel 101, which function to communicate hydraulic pressure from pumps 86 and 87 with various ones of the hydraulic motors and hydraulic cylinders of the apparatus. In order to accommodate the operator, control panel 101 is positioned at a level convenient for the operator to walk behind the apparatus and manipulate various ones of the control valves, or sit in chair 104 and ride with the apparatus as it performs its cribbing function, or as it travels along the track. As a further convenience to the operator, a tool box 106 is connected to frame 11, adjacent engine 81 and sump 100, and rail 108 is loosely supported from frame 11. Rail 108 can be removed from the frame and positioned across the cross ties as a substitute for a rail of the track which has been previously removed. Thus, rail 108 can function as a substitute for a previously removed rail of the track.

As is shown in FIG. 8, pumps 86 and 87 are connected to engine 81 and clutch 84 and function to withdraw hydraulic fluid from sump 100 and through filter 110 to pressurize the conduits of the system. Pump 86 urges hydraulic fluid through conduit 111 and its check valve 112 to control valves 102. Control valves 102 are connected to conduit 111 in header fashion, and communicate back with sump 100. Valve 102a communicates with hydraulic cylinder 78 of jack 75 through conduits 78a and 78b. Valve 102 is a three position valve, and is movable to pressurize either line 78a, or 781), while communicating the opposite line with sump 100, or is movable to a neutral position where neither line 78a nor 78b is pressurized.

Valve is similar to valve 102a and communicates through conduits 28a and 28b with hydraulic cylinder 28 of crawler 21. Valve 1020 is a two position valve and communicates through conduit 4811 with one side of hydraulic cylinder 48 of cribber 44. Valve 102d is similar to valve 102c and communicates through conduit 49a with hydraulic cylinder 49 of cribber 45. Valve 102a is similar to valve 1020 and communicates through conduit 70a with hydraulic motor 70, and valve 102 is similar to valve 1020 and communicates through conduit 71a with hydraulic motors 71 of cribber 45. Hydraulic cylinders 48 and 49, and hydraulic motors 70 and 71 each communicates with sump 100, so that the hydraulic fluid displaced in each of these elements by manipulation of their respective valves will flow to the sump. In order to control the rate with which hydraulic cylinders 78, 28, 48, and 49 allow their respective piston to move in a downward direction, needle valves 78c, 28c, 48c, and 490 are positioned in conduits 78a, 28a, 48a, and 49a, respectively, to control the flow of hydraulic fluid through these lines, and thus the rate of downward movement of the pistons within each of the hydraulic cylinders. With this arrangement, a smooth downward movement of each of the mechanisms controlled by the hydraulic cylinders will be attained, without the hazard of dropping and damaging these mechanisms.

Pump 87 functions to pressurize conduit 115, which includes check valve 116 relief valve 118, shut-off valve 119, and control valve 120. Control valve 120 communicates with conduits 121 and 122 and exhaust conduit 124. Exhaust conduit 124 communicates with sump 100, while conduits 121 and 122 communicate with wheel drive motors 16 and 17, and crawler motors 41 and 42. Both conduits 121 and 122 communicate with adjustable flow regulator 125, through check valves 126 and 127, respectively. Adjustable flow regulator 125 functions to regulate the pressure and velocity of the hydraulic fluid flowing through conduits 121 and 122, and communicates with sump 100. When reversible control valve 120 is in one position, conduit 121 will be pressurized, while conduit 122 will communicate with relief conduit 124 and with sump 100; whereas, when reversible control valve 120 is positioned in its opposite position, conduit 122 will be pressured, while conduit 121 will communicate with relief conduit 124 and sump 100. Thus, assuming conduit 121 as pressurized and conduit 122 as communicating with sump 100, the hydraulic fluid will flow through conduit 121 toward crawler motors 41 and 42. The liquid displaced from crawler motors 41 and 42 will flow through conduit 129, its flow control valve 130, through shut off valve 131, through balance valve 132, and back to conduit 122 and sump 100. Conduit 121 also communicates with conduit 134, flow divider valve 135, conduits 136 and 137, to wheel motors 16 and 17. Wheel motors 16 and 17 communicate through conduits 138, 139, and 140 with conduit 122, and sump 100. Balance valves 141 and 142 are positioned in conduits 139 and 136, to regulate the flow through these conduits. Thus, when control valve 120 is positioned to pressurize conduit 121 and to communicate conduit 122 with sump 100, hydraulic motors 41 and 42 of crawler 21 and hydraulic motors 16 and 17 of Wheels 12c-d will be motivated to drive the cribbing apparatus along a railroad bed. If all four wheels 12a-d are in contact with the rails of the track, cut off valve 131 can be closed to de-energize hydraulic motors 41 and 42 of crawler 21. In the event that it is desirable to reverse the direction of rotation of the cribbing apparatus control valve can be reversed, and the flow of hydraulic fluid through the system will be reversed to reverse the direction of motors 16, 17, 41 and 42. The balance valves of the system are constructed so as to balance the flow of hydraulic fluid therethrough, regardless of the direction of flow.

In the event that one of pumps 86 and 87 should become damaged, conduit 144 connects conduit 115 with conduit 111, and cross over valve 145 establishes or terminates communication between conduits 111 and 115, as desired. In this manner, one of the pumps 86 and 87 can be utilized to drive all of the hydraulic cylinders and motors of the system.

The balance valves of the system of pump 87 are arranged to that hydraulic motors 16, 17, 41, and 42 will be motivated or driven at the same rotational speed, so

that crawler 21 will operate in unison with wheels 12a-d. Thus, there will be no danger of crawler 21 becoming unbalanced with respect to wheels 12a-d, and causing the cribbing apparatus to pull off its track.

OPERATION When it is desired to operate railroad bed cribber 10, clutch 84 is disengaged, and internal combustion engine 81 is started in the conventional manner. After engine 81 has been started, clutch 81 is reengaged, and pumps 86 and 87 are energized. Control valve 120 is then moved to a position to drive railroad bed cribber 10 in the direction as desired. Motors 16 and 17 of wheels 12a-d will be energized, while motors 41 and 42 of crawler 21 will be de-energized by closing cut off valve 131.

When railroad bed cribber 10 has reached the area which is to be cribbed or excavated, the rails ahead of railroad bed cribber 10 on the side of the track beneath crawler 21 are removed from the railroad bed. Control valve 102a is manipulated to pressurize conduit 78a, which pressurizes hydraulic cylinders 78- and moves jack 75 in a downward direction with respect to frame 11, into engagement with the railroad bed, whereupon railroad bed cribber 10 is lifted from rails and 151. The rail section of rail 151 immediately beneath railroad bed cribber 10 is removed from the railroad bed, and control valve 102a is manipulated to allow jack 75 to lower railroad bed cribber so that its wheels 12c and 12d rest on rail 150. Control valve 1021) is then manipulated to pressurize hydraulic cylinder 28 and urge crawler 121 in a downward direction until it engages cross ties 152, to

support railroad bed cribber 10. Control valve 102a is then again manipulated to lift jack 75, so that frame 11 is supported entirely by wheels 12c and 12d, and by crawler 21 in a three point suspension. Control valves 102a and 102d are then manipulated to allow cribbers 44 and 45 to move down into engagement with the railroad bed. Locking chains 56 and 57 are adjusted so that cribbers 44 and 45 will be held from excessively penetrating the railroad bed. Control valve 102e and 102) are then manipulated to energize cribber drum motors 70 and 71, which causes cribber drums 60 and 61 to rotate and perform the cribbing action.

Cut off valve 131 is opened, and control 120 is then manipulated to cause wheel motors 16 and 17 and crawler motors 41 and 42 to rotate in the desired direction to move railroad bed cribber 10 along the track as the cribbing of the road bed takes place.

Under some circumstances it may be desirable to use cribbers 44 and 45 simultaneously, as where cribber 45 may perform the initial cribbing function to roughly crib the road bed, and cribber 44 follows cribber 45 to complete the cribbing operation. On the other hand, the tines 65 of one cribber may become worn or broken, and in need of repair, and the other cribber can continue to operate while the worn or damaged cribber can be repaired.

When the cribbing function has been completed on one side of the railroad bed, control valve 120 can be manipulated to terminate the movement of railroad bed cribber along the railroad bed, control valves 102a, d, e, and f can be manipulated to terminate the cribbing function and lift cribbers 44 and 45 out of engagement with the railroad bed, and control valve 102a can be manipulated to energize jack 75 to lift railroad bed cribber 10 above rails 150 and 151, whereupon the rail sections of rail 151 can be replaced beneath railroad bed cribber 10. Control valve 102a can again be manipulated to lift jack 75, whereupon wheels 12ad will rest on the rails again. If it is desired to turn railroad bed cribber 10 around so that it cribs or excavates the other side of the railroad bed, control valve 102a can be manipulated to energize jack 75 and lift railroad bed cribber 10 from the rails, whereupon the operator merely pushes frame 11 to pivot railroad bed cribber 10 about its jack 75, and turn the apparatus around.

The structure of railroad bed cribber 10 is such that it can be easily reversed to crib either side of the railroad bed, and the cribbing function is performed with frame 11 maintained in an upright balanced position, such that railroad bed cribber 10 will normally not tend to wander off rail 150 during the cribbing function. The depth at which the railroad bed is cribbed is easily controlled by means of hydraulic cylinders 48 and 49, and locking chains 56 and 57. Furthermore, the elevation of crawler 21 can be easily controlled and adjusted so that railroad beds having different height rails can be cribbed without having the cribbing machine tilted or unbalanced.

It will be obvious to those skilled in the art that many variations may be made in the embodiment chosen for the purpose of illustrating the present invention without departing from the scope thereof as defined by the appended claims.

I claim:

1. Apparatus for removing material from between cross ties of a railroad bed comprising, a frame, wheel means at the ends of one side of said frame for supporting said one side of said frame from a rail, crawler means positioned intermediate the ends of and on the other side of said frame for supporting said frame from the railroad bed, digging means on opposite sides of said crawler means and on said other side of said frame, and support means movably supporting said digging means from said frame such that said digging means are movable under the force of gravity in a downward direction to a predetermined position with respect to said frame to engage the railroad bed.

2. The invention of claim 1 and further including means for driving said wheel means and said crawler means at a substantially equal rate.

3. The invention of claim 1 wherein said digging means includes a plurality of loosely held spokes rotatable about an axis extending longitudinally of said frame, and a housing open at its bottom and extending over said spokes.

4. The invention of claim 1 wherein said digging means are supported from said frame by upwardly extending tracks and track engaging rollers, and further including power operated means for raising said digging means with respect to said frame.

5. The invention of claim 4 wherein said tracks are connected to opposed sides of said digging means and each define a beveled edge, and wherein said rollers are connected to said frame and are V-shaped and receive the beveled edge of said rollers.

6. The invention of claim 1 and further including jack means connected to the central portion of said frame and arranged to lift the frame from the railroad bed.

7. The invention of claim 1 and further including hydraulic pressure means for lowering and raising said crawler means with respect to said frame, hydraulic pressure means for raising said digging means, and means for locking said crawler means and said digging means in elevated positions with respect to said frame.

8. The invention of claim 1 and further including hydraulic motors for driving said wheel means, hydraulic motors for driving said crawler means, and a common source of hydraulic pressure for energizing all of said hydraulic motors.

9. Apparatus for removing material from between the cross ties of a railroad bed comprising:

a frame,

a wheel at each corner of said frame for supporting said frame from a railroad track,

a crawler connected to one side of said frame intermediate the wheels of said one side,

hydraulic power means for urging the crawler in a downward direction to an operative position below the wheels of said frame and for lifting the crawler above the wheels,

hydraulic motor means for driving all the wheels and the crawler of said frame at substantially equal speeds,

a pair of digging means positioned on said one side of said frame, one each on opposite sides of said crawler,

hydraulic motor means for driving each of said digging means,

hydraulic power means for lifting said digging means with respect to said frame and means for locking said digging means in an elevated position,

a jack supported centrally of said frame, and

hydraulic power means for urging said jack downwardly with respect to said frame and into engagement with a railroad bed to lift said frame above said railroad bed and for raising said jack upwardly with respect to said frame and out of engagement with the railroad bed.

10. Apparatus for removing material from between the cross ties of a railroad bed comprising:

a frame,

a wheel at each corner of said frame for supporting said frame from a railroad track,

a crawler connected to one side of said frame intermediate the wheels of said one side,

hydraulic power means for urging the crawler in a downward direction to an operative position below the wheels of said frame and for lifting the crawler above the wheels,

hydraulic motor means for driving all the wheels and the crawler of said frame at substantially equal speeds,

a pair of digging means positioned on said one side of said frame, one each on opposite sides of said crawler,

hydraulic motor means for driving each of said digglng means,

hydraulic power means for lifting said digging means 'with respect to said frame and means for locking said digging means in an elevated position,

a jack supported centrally of said frame,

hydraulic power means for urging the jack downwardly with respect to said frame and into engagement with a railroad bed to lift said frame above said railroad bed and for raising said jack upwardly with respect to said frame and out of engagement with the railroad bed,

a source of hydraulic fluid,

first pump means communicating with said source and with each of said hydraulic motor means for energizing each of said hydraulic motor means,

a second pump means communicating with said source and with each of said hydraulic power means for energizing each of said hydraulic power means, and

valve means connected between said first and second pump means for selectively connecting all of said 9 hydraulic motor means and all of said hydraulic power means to a single one of said pump means.

References Cited UNITED STATES PATENTS Bager et a1. 105-215 Robb 105-215 Flowers 105-215 Vodoz 105-215 Austin 37-105 X Philbrick 105-215 Praytor et a1. 37-104 Perazzoli 37-104 Kershaw 37-104 FOREIGN PATENTS France. France.

10 ROBERT E. PULFREY, Primary Examiner E. H. EICKHOLT, Assistant Examiner US. Cl. X.R. 

